"Flex Fuel" Tundras and 5,000 mile OEM oil change interval?

[sixdogs]

I have a 2011 Toyota Tundra V8 that is a so-called Flex Fuel vehicle in that it can run on E85, something I would never do. In fact, I would run exclusively on E0 if it were more widely available. The OEM on these Tundras mandates a 5,000 mile oil change with a flex fuel engine. Period. End of discussion. By the way, I run Mobil1 5W30 and tow 1/4 of the time.

Come on, this doesn't make sense. I know the oil has lots of life in it so what's so special about a flex fuel vehicle that means change the oil at 5,000 miles in a 7,500 or 10,000 world? Do we go to He** for failure to comply? Find our beds short sheeted at night? Maybe the engine takes a powder and throws a rod through the pan?

None of that seems likely so does anyone know?



**Come to think of it, my 2015 Tacoma 4 cylinder regular fuel engine also mandates 5,000 mile oil change. Surely, I'm the only one out of the loop here and I don't get it.

 

[RandyT]

My 2011 Ram 1500 with the Hemi calls for 8000 mile oil changes, but I try to change the oil everything 5000 or so. Heck if I listened to the dealer and pay attention to their oil change sticker on the windshield they would have me changing it every 3000 miles.

 

[Wolfy]

Seems to me 5,000 mile oil changes makes nice round numbers to help remember when to do it.

 

[Gary Fowler]

Most vehicles now come with a oil change computer that tells you when to change based on engine RPM, engine temps and other use related items. Every new car I have bought since 2003 has these and my dealers always tell me to just change it when the computer tells you to OR once a year. The computers are based on using regular oil so if you use a synthetic, you could go further.
I base all my oil changes off the computer since I have the old age syndrome of CRS anymore. I do write the date of change on any filter that can be seen without removal. I have one car that is impossible to see the filter, well maybe if I jacked it up, scooted under it and looked up thru the frame hole that allows you to reach the filter. Then with the help of a strong flashlight I might be able to see the bottom of the filter, but why work so hard at it when the computer tells me when I need to change

 

[tcartwri]

Wouldn't doubt it has something to do with Toyota getting sued for oil sludge engine failures in the nineties and early 20's

 

[sixdogs]

Kind of a side thing here, I keep a notebook with all info regarding oil change, any filter change, tire rotation and other info like part numbers or tire pressures or oil/trans capacities. Come showtime, I'm good to go in a moment's with whatever I need for info. Saves money, time and memory.

 

[Toyboy]

I'm a Mobil 1 guy myself. I'll spin a new filter on between 3 to 3.5k and a complete change out @ 9k. Been doing it this way for close to 30 years now.

 

[houstonscott]

Just bought a new Land Cruiser (5.7) , calls for oil change every 10k miles! I changed brake in oil at 1500, and plan on every 5k. Takes that new 0/20 oil, that scares me in Texas heat.

 

[3930dave]

I have a 2011 Toyota Tundra V8 that is a so-called Flex Fuel vehicle in that it can run on E85, something I would never do. In fact, I would run exclusively on E0 if it were more widely available. The OEM on these Tundras mandates a 5,000 mile oil change with a flex fuel engine. Period. End of discussion. By the way, I run Mobil1 5W30 and tow 1/4 of the time.

Come on, this doesn't make sense. I know the oil has lots of life in it so what's so special about a flex fuel vehicle that means change the oil at 5,000 miles in a 7,500 or 10,000 world? Do we go to He** for failure to comply? Find our beds short sheeted at night? Maybe the engine takes a powder and throws a rod through the pan?

None of that seems likely so does anyone know?



**Come to think of it, my 2015 Tacoma 4 cylinder regular fuel engine also mandates 5,000 mile oil change. Surely, I'm the only one out of the loop here and I don't get it.

I can think of 2 reasons. First, Toyoda being conservative in their spec, possibly partly in response to sludge problems in certain motors. You use a quality oil 6d, but not everybody does. Toyota may want to over-spec the oil interval (therefore, just about any oil will do), rather than have to argue with customers about out oil quality.

The other issue is the alcohol itself. Don't know if your motor is DI, but regardless, fuel dilution can be a concern with E85. OLM computers should be programmed to deal with such things, but let's say a truck spends all Winter in northern Canada doing short-trip cold-starts - it will spend most of the time running relatively rich at that temperature. In an extreme case like that, I can see why they'd want the oil changed sooner with E85.

Rgds, D.

 

[Ford850]

My F150 5.0 is flex fuel. They list no difference in oil change frequency regardless of fuel, but do say to run a tank of Unleaded gas through it at every oil change (if running E85 exclusively). Change intervals for extreme use (dusty sandy, etc) is 5k miles, otherwise 10k I believe.
I ran 2 tanks of e85 in the early fall, back to back, to act as a system cleansing.